WLAN products have evolved immensely over the years. Some can be feature rich. Others provide just basic functionality in order to reduce costs. Cost savings are most likely realized in the hardware, so it is there where different WLAN products may not be compatible.
802.11b and 802.11g WLAN products operate in the 2.4 GHz frequency range. 802.11a WLAN products operate in the 5 GHz frequency range. A device which supports only 802.11b will not be able to communicate with one that supports only 802.11a. 802.11g maintains backwards compatibility with 802.11b, so an 802.11g device will be able to communicate with an 802.11b device. When first introduced, 802.11g WLAN products were advertised as 802.11bg, but that may no longer be the case.
802.11n is often advertised in a way that causes confusion regarding interoperability. The 802.11n standard does not introduce a new frequency range. Logically, the features defined by the standard can be thought of as operating over existing 802.11a, b, and g technologies. 802.11n maintains backwards compatibility, so a device supporting 802.11n can communicate with one that does not as long as they both can operate over the same frequency range (e.g. both support 2.4 GHz or 5 GHz).
Many WLAN products are designed to meet multiple standards (e.g. Intel® Wireless WiFi Link 4965AGN). The user should consider the possible WLAN environments they’ll encounter when selecting an Intel® WiFi adapter. Choosing products that are Wi-Fi compliant should also help insure interoperability.
This applies to: